Cradle assembly for stranding machine



Nov. 15, 1960 c. o. BRUESTLE CRADLE ASSEMBLY FOR STRANDING MACHINE 2Sheets-Sheet 1 Filed Feb. 24, 1958 INVENTOR. $421 0. flea/5745 BYflffd/Q/VEKI' United States Patent CRADLE ASSEMBLY FOR STRANDING MACHINECarl 0. Bruestle, Metuchen, N.J., assignor to Synchro Machine Company,Perth Amboy, N.J., a corporation of New Jersey Filed Feb. 24, 1958, Ser.No. 717,197

4 Claims. (Cl. 57-65) The cradle assembly of this invention forms partof a cable stranding machine.

These machines are well known in the art in various forms and areprovided for the purpose of building up relatively large twisted cablescomposed of a plurality of smaller strands which are fed concurrently tothe nosepiece of the machine. The twisting of the strands into the cableproper is effected by rotating the main shaft of the machine on whichare in turn rotatably mounted a plurality of cradles constructed tosupport supply spools for the strands. The cradles are rotatably mountedon axes which are radially offset from the axis of the main shaft of themachine, so that the cradles rotate bodily about that axis as they inturn rotate each on its own axis, which is parallel to the axis of themain shaft.

Each cradle is constructed so as to in turn rotatably support the strandspool thereon, the .axis of which rotation for each cradle is at rightangles to the axis of rotation of the spool. The cradle assemblies andloaded spool strands are relatively heavy, with the result that theirplanetary motion about the axis of the main shaft of the machine resultsin the development of very large operational stresses which in turnrequire not only a heavy construction for the main parts of the machinebut also for the cradles.

As is well understood in the art the cradle frames, due to the reversalof forces encountered as they revolve bodily about the axis of the mainshaft, alternately subice: the side members of the cradles to rapidlyand successively occurring maximum and minimum stresses. Thus since eachside member of the cradle is alternately subjected to a maximum stress,each cradle has to be of sufiiciently heavy construction to withstandsuch stresses.

A prime purpose of this invention is to provide a novel arrangement inwhich the side frame members of each cradle are cross-connected or tiedtogether during operation of the machine so that the stresses applied toone side member Will be transmitted to and divided with the other sidemember. This shifting of stresses occurs alternately as the cradlerevolves not only about the axis of the main shaft of the machine, buton its own axis.

Further, in accordance with this invention the crossconnection of theside frame members of the cradle is effected by means of a tie bar whichlies axially of the strand spool, rotatably mounted on the cradle, andpasses through the core of the spool so that it may not escape from thecradle during the operation of the machine.

Further in accordance with this invention it is proposed to provide aconstruction in which the bearings for rotatably supporting the strandspool are capable of endwise movement with respect to each other underthe influence of the tie bar, so that when the spool is mounted thesebearings, which are the radial thrust type, are preloaded withoutstressing the side frame members of the cradle.

Further in accordance with this invention, provision is made, after thespool is mounted in the cradle, for

2,959,907 Patented Nov. 15, 1960 2 locking the bearing assembliestherefor in the cradle so that cooperation with the tie barcross-connection of the side frame members is effected for transferenceof the stresses back and forth in the operation of the machine.

Other and more detailed objects of the invention will be apparent fromthe following description of the embodiment thereof illustrated in theaccompanying drawings including the advantage that by this constructionthe cradles may be of lighter construction than otherwise possible.

In the accompanying drawings, 7

Figure 1 is an elevational view of sufiicient part of a planetary cablestranding machine to illustrate this. invention showing one of thecradles in the plane with the strand spool mounted therein;

Figure 2 is a side elevational view of the cradle; and

Figure 3 is a cross-sectional view taken on the line 33 of :Fig. 1.

As diagrammatically illustrated, a planetary cable stranding machineincludes a main rotor shaft 10, which is rotatably mounted in bearings,not shown, and which is provided at the cradle positions with radialarms or spiders 11 and 12. Rotatably mounted in suitable bearings 14 and15, at the outer ends of these arms, is the cradle which is generallyindicated by the reference numeral 13. This cradle is thus rotatablymounted on its longitudinal axis at the ends of the arms 11 and 12.

The cradle 13 is a generally-rectangular open frame which includes theside frame members 19 and 20, formed to provide a pair of alignedbearing housings 17 and 18.

on the unflanged end of that sleeve. Interposed between the race pairs21 and 22 are aseries of tapered bearing rollers 25 and 26 mounted inanysuitable form of roller cages in accordance with well understoodpractice in'the bearing art.

Secured by means of machine screws, as shown inFig. 3, on the flangedend of the sleeve 23, is a truncated conical nosepiece 27. Also mountedon the sleeve attached to the nosepiece is a grooved pulley 28 whichforms part ofthe. usual friction brakecommonly used in machines of thistype but of no special importance herein. Projecting from the lefthandface of the pulley is a pin 29 adapted to engage a suitably positionedaper ture in the end member of the strand spool 61, so as to insureconjoint rotation of the spool 16, with the nosepiece 27 and the partsconnected thereto.

Attached over the end of the recess in the bearing housing 17 for therighthand pintle assembly, is a cap disc 30, secured in place by machinescrews, as shown. The disc 30 has a central threaded aperture for apurpose to be described later. At 50 is a fixed ring, secured to theside frame member 17 and forming an annular channel with a radiallypositioned flange on the pulley 28 in which is mounted a sealing ring 51to seal the bearing assembly at the end opposite to the disc 30.

In the bearing housing 18 is slidably mounted a sleeve 31 forming partof the lefthand pintle assembly. Mounted in this sleeve, in suitablyshaped and positioned seats are a pair of outer bearing races 33, whichcooperate with a pair of inner bearing races 34 to provide seats for thetapered bearing rollers 35 and 36 held in roller bearing cages. Theinner races 34 are mounted on a rotatable sleeve 48 which is providedwith a truncated conical nosepiece 37 secured to its end, by means ofmachine srews, as shown. These races are confined to the sleeve at theother end by means of a flange 38 integral with the sleeve 48. An axialmotion limit stud, in the form of a machine screw 50 is threadedlymounted in the side frame member 18 and projects into a slot 49, in thesleeve 31, closed at its ends. This stud prevents the sleeve fromescaping from the frame member while permitting sliding movementtherein.

In a concentric recessed seat at the lefthand end of the sleeve 31 is adisc 39 secured in that place by means of machine screws, as shown. Thisdisc has a concentric passage aligned with the passages in the sleeves48 and 23 to permit the passage of a headed tie bar 40 therethrough. Theunheaded end of the tie bar is threaded, as at 41, to engage the threadsin the central bore of the disc 30. The enlarged end 42 of the tie baris provided with a hexagonal shape, as illustrated.

As illustrated in Fig. 2, the sleeve 31 can be locked in various axialpositions in the bearing housing 18 by means of a pair of threadedblocks 43 lying in a cavity formed in the frame member 20. These blocksare provided with reversely threaded passages and a clamp bolt 44 havingproperly positioned reversely threaded sections engaging the threads ofthe clamping blocks.

A spool is mounted in the cradle by releasing the clamping blocks 43,removing the tie bar 40 and sliding the lefthand pintle assembly 31 tothe left. The reel which has a hollow barrel or core is then positionedso that at one end it engages the nosepiece 27, whereupon the pintleassembly 31 is slid back to the right so that its nosepiece 37 engagesthe other end of the spool barrel. The tie bolt 40 is replaced and drawnup tight, causing the spool to be clamped between the nosepieces. Theends of the spool barrel are preferably tapered to cooperate with theconical formation of the nosepieces, with the result that the spool willbe centered concentrically with the axes of the pintles.

As the tie bar is drawn up tight the bearings nearest the nosepieces 27and 37, respectively, are preloaded and this results in the fact thatthe tie bar pulls the lefthand pintle assembly towards the righthandpintle assembly fixed in the frame member 17. Upon the completion ofthese procedural steps it will be seen that the side frame members 19and 20 are not tied together or preloaded. The clamping blocks 43 arethen drawn up tight to prevent any rotational or axial movement of theleft hand pintle assembly. The bearings remain preloaded and the spool,of course, is clamped between the nosepieces, but the side framemembers, are not stressed by the tie bar under static conditions.

On the other hand, when the machine is in operation and subjected to thestresses discussed at the beginning of this disclosure, the stresses,which are alternately ap- 4 plied to the side frame members, will bedivided between. them. To state this condition a little differently, asthe stresses build up to a maximum in one side frame member, it will bedistributed or transferred to the relatively unstressed side member andthis condition will alternate back and forth as the machine operates.Thus, it is possible to make the cradle of a lighter construction thanwould be required were it not possible to divide the operational loadsbetween both side frame members.

If centrifugal force acts toward the right, the bearing nearest disc 27will be loaded by it in addition to its pre-load. The tie bar dividesthis additional load with the opposite frame member only.

Other types of bearings may beused instead of Timken, as shown.

From the above description, it will be apparent to those skilled in theart that the details of the structure selected herein to exemplify thisinvention may be varied by those skilled in the art without departurefrom the novel combination and functional cooperations thereof. It isdesired, therefore, that the scope of protection afforded hereby bedetermined by the appended claims.

What is claimed is:

1. In a cable stranding machine, a rotatable spool sup porting cradlehaving a pair of side frame members, a pintle assembly fixed in one ofsaid members including a rotatable spool supporting fixture journaled ina thrust bearing, a second pintle assembly slidably mounted in the otherframe member and including a pair of concentric sleeves having a thrustbearing interposed therebetween, the inner sleeve having thereon arotatable spool supporting fixture, tension means engaging the outersleeve of said second pintle assembly and the opposite frame member forpreloading said bearings while clamping a spool between said fixtures,and means for locking said second pintle assembly against movement inits frame member.

2. In the combination of claim 1, said tension means comprising a tiebar threadedly engaging said opposite frame member.

3. In the combination of claim 1, said tension means comprising a tiebar lying coaxially of said pintle assemblies.

4. In the combination of claim 1, said tension means including a tiebar, a seating plate engaging the outer end of said outer sleeve andengaged by the tie bar at one end, and a plate secured to the outer faceof the opposite frame member and engaged by said tie bar.

References Cited in the file of this patent UNITED STATES PATENTS2,681,544 Bruestle June 22, 1954 2,787,884 Bruestle Apr. 9, 19572,860,479 Wheater Nov. 18, 1958

